Instrument for measuring fluids for turbidity, color, and other characteristics



' 1 6'44 331 Oct. 4, 1927.. G EXTON INSTRUMENT FOR MEASURING FLUIDS FORTURBIDITY,

COLOR, AND OTHER CHARACTERISTICS Filed Oct. 23, 1925 3 Sheets-Sheet 1 IN V EN TOR. 'fi' l w 1 km Jail/ 9 gifms ATTORNEYS.

W. G. EXTON dot. 4. 1927;

INSTRUMENT FOR MEASURING FLUIDS FOR TURBIDITY,

COLOR, AND OTHER CHARACTERISTICS Filed Oct. 23, 1925 3 Sheets-Sheet 2INVENTOR. flijrtow,

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COLOR, AND OTHER CHARACTERISTICS Filed Oct. 23, 1925 i5 Sheets-Sheet 3IN V EN TOR.

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" wedge, by bringing Patented Oct. 4, 1927.

UNlTED STATES PATENT OlEFlCE.

WILLIAM G. EXTON, OF NEW YORK, N. 'Y.

INSTRUMENT FOR MEASURING FLUIDS FOR TURBIDITY, COLOR, AND OTHERCHARACTERISTICS.

a Application filed October 23, 1925. Serial No. 64,364.

This invention relates, generally, to an instrument for measuringturbidities, colors and other characteristics of fluids by opticalobservation.

Heretofore the principles underlying the structure and operation ofmeasuring instruments for the purposes mentioned, have been based onwhat may be termed a comparison method, whereby a fluid of unknownturbidity, color, etc., is sub ected to comparison with a fluid of knowncharacteristics or with a prepared standard Titlld, and in some cases,the unknown fluid is sub ected to comparison with a prepared or standardthe unknown fluid into a parallel visual field with the wedge, thelatter being shifted until the unknown fluid matches some point on thewedge, the thickness of the wedge at the matching point furnishing themeasurement by calibration. In order to provide an instrument formeasuring the characteristics of fluids which is based on a method lesscomplicated and more easily and rapidly practiced than the aforesaid comarison method, I have here tofore invente and have disclosed in myco-pending applications Ser. No. 570,409, filed June 23, 1922, and Ser.No. 644,6il2, filed June 11, 1923, instruments operating by adisappearance method, wherein a target mark is viewed through a columnof the unknown fluid to be measured, and the criterion of measurement isthe determmat1on of the depth of fiuid at which the target markdisappears. In these instruments the measurement is determined by afiuid depth criterion. In my present invention, 1 have devised a verysimple instrument which operates on a principle similar to that enployed in my heretofore mentioned prior 1nventions, except that themeasurement is determined by a wedge criterion instead of a fluid depthcriterion; the wedge producing additive visual eflects upon the fluidexamined, when the latter and the wedge are together interposed betweenthe eye and an illuminated target, to cause the disappearance of thetarget mark or absorption of color according to the specific characterof 0 the wedge; the thickness of wedge required to effect thedisappearance of the target mark or absorption of color, as the casemaybe, furnishing the measurement by calibration.

My present invention, therefore, has for its principal object to providean instrument 0t simple construction, comprising a casing having aneye-piece at one end, and having its opposite end open to the admissionof light tor the illumination of a suitable target mounted within theouter end portion of the casing. The casing is further provided withmeans to support a transparent fluid receptacle, such as a test tube, infront of said target, and interposed between the fluid receptacle andthe eye-piece is an adjustable measuring wedge consisting of a suitablymounted bod having a linear slope from end to end, said wedge being ofprogressively lncreasmg density from one end toward the other to providea gradually increasing degree of opacity progressing from an initialsubstantlally transparent condition, or a gradually increasing intensityof color. The novel arrangement thus provided permits the tar et to beviewed through the inter posed fluid to be measured and the wedge, andthe latter being subject to manipulation and adjustment producesadditive density suflicientto cause the disappearance of the target markor absorption of color as the measuring condition or point readable on ascale arranged in connection with the wedge, and adapted to vary as thedensity of the latter varies.

Other objects of this invention, not at this time more articularlyenumerated, will be clearly an erstood from the following detaileddescription of the same. i

The invention is clearly illustrated in the accompanying drawings, inwhich 1- Figure 1 is a rear end elevation of my novel construction ofinstrument; Figure 2 is a side elevation of the same; Figure 3 is anouter end elevation of the same; Figure 4; is also an outer endelevation of the same, with the separable outer diaphragm thereofremoved; Figure 5 is a longitudinal vertical section of my novelinstrument, drawn on an enlarged scale; Figure 6 is a transversesection, taken on line X--X, looking in the direction of the arrow y;and Figure 7 is also a transverse section, taken on line X- X, lookingin the direction of the arrow 2.

Figure 8 is a rear end elevation of my novel construction of instrumentprovided with a modified species of adjustable wedge and inner diaphragmadapted for practicing colorimetry, or measurement of fluids for color;Figure 9 is a longitudinal vertical section of my instrument with themodified species of color measuring wedge; Figure 10 is a transversesection, taken on line 1010 in Figure 9.

Similar characters of reference are employed in all of the hereinabovedescribed views, to indicate corresponding parts.

Referring now to said drawings, the reference character 11 indicates alongitudinal casing, preferably of cylindrical form, the same beingclosed at its rearward or inner end by a cap 12, which is threaded intoor otherwise secured to the casing end. Centrally connected with saidcap 12, so as to be axially alined with said casing 11 is an eyepiece,comprising a cylindrical barrel 13 of reduced diameter, provided at itsforward inner end with a suitable lens 14, and at its outer or rearwardfree end with an apertured end member 15.

Fixed within the interior of said casing 11, to extend transverselyacross the same is a diaphragm 16 having a central openingl7 alignedwith said eye-piece. Connected with the forward side of said fixeddiaphragm 16 are a air of laterally spaced vertical guide mem ers 18adapted to provide a measuring wedge slideway. The walls of said casing11, above and below said slideway, are provided with openings 19 and 20which are aligned with said measuring wedge slideway.

Adjustabl movable through said slideway, provi ed b the guide members18, and through sai openings 19 and 20 is a measuring wedge. The saidmeasuring wedge may be varied as to its specific character according tothe articular characteristic of an unknown uid it is desiredto measure,as will be hereinafter more fully set forth.

Transversely disposed within the open outer end of said casing 11 isatarget member. Said target member is supported by a keeper ring 21,which surrounds the marginal portions of the same, and holds the same inposition against an internal annular seating ferrule 22. It will beunder stood, however, that any other desired form of target supportingmeans may be em.- ployed. The target member preferably comprises atransparent panel or disc, preferably made of glass, having a centrallydisposed opaque target spot 23, which may be produced by silvering thecentral portion of the panel or disc, and within which spot 23 isproduced a small transparent target mark 24:. The marginal portion 25 ofsaid panel or disc, which surrounds said opaque target spot 23 istransparent so as to permit the passage of light therethrough.

The in per wall of the casing 11, at a point intermiate the targetmember and the measuring wedge, is provided with an opening 26surrounded by an upstanding annular flange 27, through which may beinserted a transparent receptacle 28. such as a test tube, adapted tocontain the fluid to be measured. Connected with the underside wall ofthe casing 11, and within the interior of the latter, is a suitable seatmember 29 to engage and support the receptacle 23, when the latter isinserted through the flanged opening 26. If desired, the said flange 27may be partially cut through hori zontally, as at 30, and its upperportion vertically divided to provide a pair of springlike gripping aws31 for engaging and holding the receptacle 28 against accidentaldisplacement from operative inserted relation to the casing 11.

WVhen the receptacle 28, charged with the fluid to be measured. isinserted through said flanged opening 26 into the interior of saidcasing 11. the contained fluid will be interposed in the line of visionintermediate the target member and the measuring wedge.

WVhen the instrument is to beyused to measure a fluid for turbidity, themeasuring wedge employed comprises a translucent body 32 possessing alinear slope from end to end, the same being treated to provide aprogressively increasing degree of opacity extending onward from aninitial substantially transparent condition at its thin end. A wedgehaving the described characteristics may be produced from a collodionmaterial treated with a white pigment, the density of distribution ofsaid white pigment in the collodion material progressively increasingfrom one end to the other to thereby attain the gradual increase ofopacity desired. The wedge body 32 thus characterized and of suitablelength is preferably mounted between two facing sheets of clear glass33, to thereby both protect the same against surface scratches or otherinjury, while at the same time reenforcing the wedge body to obtain therigidity necessary to convenient operative manipulations in connectionwith my novel measuring instrument. The assembled glass facing sheetsand wedge body are preferably bound together by a binding frame 34 ofsuitable construction, and preferably made of metal. Provided inconnection with the binding frame 34, or associated with the wedge bodyin any other convenient manner, is a suitably graduated scale to providereadings progressively corresponding to the increasing degrees ofopacity of the measuring wedge body.

A fluid of unknown turbidity desired to be measured is introduced intothe transparent container or receptacle 28, and then the latter isinserted into the casing 11 intermediate the target member and themeasuring wedge. Turbidities of fluids are ordinarily classified asdensities, clouds and 1 mark 24.

hazes. If the fluid to be measured possesses a turbidity classified as adensity, I insert in the outer open end of the casing 11, beyond thetarget member, a removable outer diaphragm 35 provided with an aperture36 for alignment with the opaque target spot 23. This outer diaphragmtends to concentrate the light entering the outer end of the casing uponthe target spot 23 so as to give sharp definition and brightness to thetarget The measuring wedge is slid downwardly to bring its thinsubstantially transparent end in the field of vision. The operator nowdirects the open outer end of the casing 11 toward a bright light, andapplies his eye to the eye-piece of the instrument. I

The target mark 24 is sighted through the interposed measuring wedge andturbid fluid, and appears to the e e as a bright line or spot. Theoperator sl bwly slides upwardly the measuring wedge to interpose 1n theline of vision a gradually increasing opacity, which causes the targetmark to gradually fade away and ultimately disappear. The scale of themeasuring wedge is read when the point of movement of the latter isreached which produces the disappearance of the target mark. Theresulting scale reading is compared with a table of predetermined andestablished standard readings, so that the amount of turbidity possessedby the fluid under examination is directly obtained by such reading andreference comparison.

If the fluid to be measured possesses a turbidity classified as a haze,I remove the outer diaphragm 35, thus permitting light to pass throughthe transparent zone 25 of the target member, to directly enter thatportion of the interior of the casing in which the fluid is located, theinside walls of which may be treated with a suitable light reflectingcoating, as e. g.- a coating of white enamel. In this manner, theintegrating effects of a hollow sphere principle of li ht scattering orreflections is obtained, where y the very fine turbidity or haze isbuilt up by multiple reflections from the suspended particles in thefluid to be measured, all in the manner adapted to produce the darkfield eflect familiar to microscopists. By this method the cloudiness orobstructin efl'ect of the suspended particles is increase The operatornow applies his eye to the eyepiece and manipulates the measuring wedgeuntil the target mark disappears, thereupon reading the wedge scale forcomparison with a proper table of standard readings, whereby the measureof turbidity of the fluid examined may be readily determined.

If the fluid to be measured possesses a turbidity classified as a cloud,either the first or second method of examination above set forth may beutilized.

When the instrument is to be used to measure a fluid for color, I employa modified form of measuring wedge together with a modified form ofinner diaphragm. These modifications are illustrated in Figures 8 to 10inclusive of the accompanying drawings. In place of the diaphragm 16, Iemploy an inner diaphragm 37 having a lar e central opening 38 acrosswhich is exten ed 0. diametrically disposed shield member 39 providedwith a viewing slot or aperture 40. Connected with the outer face ofsaid diaphragm 37 are the wedge slideway members or guides 18. Themodified form of measuring wedge comprises a relatively narrow wedgebody 41 to provide a color filter of a color complementary to the colorof the fluid to be examined; e. g. if a blue fluid is to be examined andmeasured for color, the wedge body 41 will be made to provide thecomplementary color red. The wedge body 41 is made so that the colorthereof gradually increases in intensity from one end to the other ofsaid wedge body. The wedge body 41, thus characterized and of a suitablelength, is mounted between two facing sheets of clear glass 42 of awidth exceeding the width of the wedge so as to provide light admittingor transmitting sections at each side of said wedge body. The assembledglass facing sheets 42 and wedge body 41 are preferably bound togetherby a binding frame 43 of suitable construction and preferably made ormetal. Provided in connection with the binding frame 43, or associatedwith the wedge body in any other convenient manner, is a suitablygraduated scale to provide readings progressively corresponding to theincreasin intensity of color of the measuring wedge body 41. The targetmember employed may be the same as that heretofore described.

A fluid of unknown color intensity desired to be measured is introducedinto the transparent container or receptacle 28, and then inserted intothe casing 11 intermediate the target member and the measuring wedge.WVhen measuring color it is desirable to prevent the transmission oflight through the fluid except at a point in the direct path of visionfrom eye-piece to target, so that the field or background upon which thecolor is shown is not influenced by the color of the fluid. To this endI enclose the lower end of the receptacle or container 28 in a sleeve 44having diametrically opposed slots 45 for alignment in the path ofvision be tween the eye-piece and target member. The measuring wedge isslid downwardly to brin its least intense complementary color portion inthe field of vision. The operator now directs the open outer end of thecasing 11 toward a bright light, and applies his eye to the eyepiece ofthe instrument. The

-l y blots out or neutralizes light admitted through the tar et mark 2%passes through the slots 45 o the sleeve 44 to illuminate the fluid atthe line of vision, so that the color effect is seen by the eye at theviewing slot or aperture 40 of the inner diaphragm 37. The lighttransmitted through the transparent zone 25 of the target member, isalso transmitted through the clear glass sections of the measuring Wedgemember on each side of the wedge body 41, thus producing the effect of awhite or light field against which the transmitted color is viewed. Theoperator slowly slides upwardly the measuring wedge to interpose in theline of vision a graduallyincreasing intensity of color complementary tothe color of the fluid under examination, which gradualthe transmittedcolor and produces a total disappearance thereof, in other wordsproduces the effect of blackness at the viewing slot or aperture 40 ofthe diaphragm 37. In order to aid the eye in determining the totalabsence of color or appearance'of blackness thus effected, the shieldmember 39 excludes all light along the edges of the viewing slot oraperture 40, to produce a permanent black zone against which theblotting out effect of transmitted and neutralized color may becontrasted to assure the eye of total absence of color. The scale of themeasuring wedge is read when the point of movement of the latter isreached which produces the disappearance of all color. The resultingscale reading is compared with a table of predetermined and establishedstandard readings, so that the degree of color intensity of fluid underexamination is directly obtained by such reading and referencecomparison.

From the above description of my present invention it will be evidentthat I have produced a very simple and easily manipulated instrument bymeans of which measurements of turbidity, color, etc., of fluids may bequickly obtained.

I am aware that some changes may be made in the several arrangements andcom binations of the various devices and parts making up my novelinstrument, as well as in the details of the construction of the same,without departing from the scope of this invention as set forth in theforegoing specification, and as defined in the appended claims. Hence, Ido not limit my invention to the exact arrangements and combinations ofthe various devices and parts as described in said specification, nor doI confine myself to theexact details of the construction of said partsas illustrated in the accompanyin drawings.

claim 1. An instrument of the kind described, comprising a casing havinga closed end provided with an eye aperture, and having its opposite endopen to the admission of light, a target member mounted within the openend of said casing, a measuring wedge transversely slidable through saidcasing intermediate said eye aperture and said target member, atransparent fluid receptacle, and means for supporting said receptaclewithin said casing intermediate said measuring wedge and said targetmember.

2. An instrumentof the kind described, comprising a casing having aneye-piece at one end, and having its opposite end open to the admissionof light, a target member mounted within the open end of said casing, aninner diaphragm having an aperture aliiied with said eye-piece locatedintermediate the latter and said target member, a measuring wedgeslidable across the aperture of said inner diaphragm, a transparentfluid receptacle, and means for supporting said receptacle within saidcasing intermediate said measuring wedge and said target member.

3. An instrument of the kind described, comprising a casing having aclosed end provided with an eye aperture, and having its opposite endopen to the admission of light, a target member mounted within the openend of said casing, said target-member comprising a light transmittingbody havmg an opaque central spot provided with a light transmittingtarget mark, a measuring wedge transversely slidable through said casingintermediate said eye aperture and said target member, a transparentfluid receptacle, and means for supporting said receptacle within saidcasing intermediate said measuring wedge and said tar et member.

4. An instrument of the kind described, compris ng a casing having aclosed end provided \vitli an eye aperture, and having its opposite endopen to the admission of light, a target member mounted within the openend of said casing, said target member comprising a light transmittingbody having an opaque central spot provided with a light transmittingtarget mark, a measuring wedge transversely slidable through said casingintermediate said eye aperture and said target member, a. transparentfluid receptacle, means for supporting said receptacle within saidcasing intermediate said measuring wedge and said target member, and aremovable outer diaphragm having an aperture aligned with the opaquecentral spot of said target member.

5. An instrument of the kind described, comprising a casing having aneye-piece at one end, and having its opposite end open to the admissionof light, a target member mounted within the open end of said casing,said target member comprising a light transmitting body having an opaquecentral spot provided with a light transmitting target mark, an innerdiaphragm having an aper- 'providid with a light:

inn; alii'rtai with said eyepiece loaned inlurmedian; ihe hill-er and:-:aid largrel inemher. a niuzlsuring hedge mllliilhll' aerosa the apexinre of :suir'i inner iliaphrinjin. a trn'na mrenl fluid reeep aele. andlllllllfi 'l'or snpportiin, :ntid i'eeir laeie n'nhin .--aid aisingintermed ate Raid inrasuriin wedge and said tar get nn-ndmr.

An imtrunienl of lhe kind des rihed. 00m ing a easing: inning an e\e-piere ai one end, and having ils opposinend open to the admin ion oflight, a target niendwr nionni'ed \vdhiu the open end o l' .--ai-leasing, said target HIQIH H'l'(HHIPI'hdIIlZi1liilllii li'an xnil'ling:body having an opaque (-enliril a n't n'ovideijl with a lightlrann-aitlin larger mark, an inner diaphragm having an aperture aiinedwith said eyeqiece located interrmdiul'e lhe laller and mid target.ineaw nring wedge slidahle arr-ms the aperture of said inner dia'ihragin. a tramnareul lluid receniaele. means for supporlimg said r llwiihin said casing interim-diam Hlhl wear-airing wedge and said targetmeinher. and a i'enioral outer diaphrznn'u having; an a arrrnre alignedwith the opaque Cen irai spol of said ni gnt nien'iher.

7. Al ininrnin ni; Lil. the kind dew-riluid comprising av mining having;a elowd end provided with an eye aperlarin enhaving its apposite endopen lo lire ndll'ilsSiUH of light a Target ineniher mounted n'ilhin theopen end of said eas ng. a \numnning wedge trans-- Yersely slidahh:lhrmngh mid easing inter mediale -\aid eye aperture and said llllglt'l',memher. Fllitl nieafiuriing Wedgi luring ehan acterized hy the pesesionnl' an haw-easing density from one end to the other, a transparent fluidreceptacle, and means for supporting said reeeptnele ithin sand casingintern'iediate aid ITIPHNHl'HQ \Ylligl and said target member;

8. An lDSlI'HIliQHl of the kind deserihed. eonnprisin; a casing; havingan lyQ-pllll a1 one end. and ha ring in opposite end open to theadmission of light a target nreniher mounted within th open end of:-:aid easing, said Larger inenil z-r ronn riding a light translnitti'ng hnily having an ujihlln renlral spot il'ii'llnlililllllgtarget mark, an inner diaphragm having an apen lure aiinedini'ernanliatn said eywpieee, and mid Marg e-i; 31! .n :nid large!vmember. a measuring \i'ed 'e eiidahle Illflfllhr the aperture of saidinner l'lixiphragzn, said measuring n'i' dgv lazing; ehararteriz ai hythe p0ssesioh. 05 an increasing densiLy from one, and to the, other, atransparent iluid receptacle, and means for supporting said mom iaelewithin said. casing intermediate said nil-naming wedge and Hit id targetmember.

9. An instrument 0! the hind described, eornprising a easing having; aneye-picee at one end and having its opposite end open to the adlniasinnol' light, a target member mounted \vilhin linopen end of said :aeing',said target nieanl er eonu'iriaing a lighi, irans niitlin liody havingan opaque eenlral spot prmidi-d with a light lranwnilling' Target inarlean inner diaphragm having an aper lure alined inl'erniwliale said e\'e-pie:-n and mark of said largz el nien'iher, a llli?l llllll wedgeslidalde arross lhe aperlnz-e ol aid inner diaphragm, -aid meanwing;\rerln'e la-inn" rharai-li ri'ljei'l l the pose---i0n ol an iaereirann dnz-dly l'roni one end to he olher. a ll'illlhlHilLlit lluid reoegt iaelmeans [or -1q porllng said revel izu'hwithin said znsiz'lg'iinerlnedialn au! nuaauring wedge and said target n1end .-er. and armnovahle outer diaphragm having an ap rture al gned with the opauuocentral spot ol' aaid target lllllil /Ll'.

Il .\n him-unreal oi, the hind deun'ilieil, a easing harin g anl-yeiiizee at, one end and a lig t l'lllll-'l'.iill ll"l;jf iargeLineniher at it:- own do end. an inner diaphragm having an ,nwrluualignedoelin'een :aiid ej.'e--pieee and hn'gjei nwnzher. a nuun-n inn wedge,:-1lidal 1h aero -a the aperlurl: of mid inner diaphragm, r aid \redgzjeheing; eharzuierixed hy the pos- :e. ion f a gradually llll'l' il :hrgdegree of opaeiiy rurnyww-iin); lil'niil an iniiiai sul rdillliilll)aran.- iiarem: ll lillli'i l. a l v d c-eplarle, and means for b lllipllilll'lfi said lluidv rw-eptaele inlerlnediale said JHL'HHISYlHQ wedgeand aid i'urgel nu-nihnr ll. An instrument of the, kind dnser hed. araisin; having an 0)'O}?l0(5 at one end and. a light trannnilring lar' inu-niher at its opposite end, an inner diaphragm hax ing a: aperlurealigned hetween aid eye-pure and larger lllinlil l" a m asuring wedgeSllLlniilu ZH'lUhH the alierlui e of aaid hue-r diaphrzninu mid wedgelining rl arm lermxd lg, the pmawsion of a gradually inureanng' degrecoi ooaeily progresflng il'ri'un an initial snlwtantially lranaparentvoniliiinn. a inid plarle, means for supporiing aid llnid reel-Pia (h:inierrne hale said nil-naming \i 'ri fll and said largei na nihe and areinorah o ouler il'lidill Mil 4 i. EXTUN.

